NY Times published an interview with Stephen Hawking today, and I found this Q/A to be very inspiring:
Q. Given all you’ve experienced, what words would you offer someone who has been diagnosed with a serious illness, perhaps A.L.S.?
A. My advice to other disabled people would be, concentrate on things your disability doesn’t prevent you doing well, and don’t regret the things it interferes with. Don’t be disabled in spirit, as well as physically.
Hawking has a point. I try to leave my regret behind. It doesn't come naturally, and I have to consciously set it aside. But, I take joy that I can still do my job and do it well.